From Wikipedia, the free encyclopedia

The Ufa train disaster happened on June 4, 1989
at 1:15 (local time) near the town of Asha in the Soviet Union on the Trans-Siberian Railway. (Ufa is a much larger and commonly known
city, which is situated not far from Asha). A liquefied petroleum gas
explosion killed 575[1] and
wounded 623 (some sources claim that up to 645[2] were
killed and more than 700 wounded), making it the most deadly
railway accident in Soviet history, as two trains passing each
other threw sparks near a leaky pipeline. Both trains were carrying
children; one returning from a holiday break on the Black Sea, one taking
children there. The explosion was so powerful it blew out windows
in Asha, eight miles (13 km) from the epicenter.[3] The
explosion is said to have been equal to 10 kilotons of TNT, almost
as powerful as the Hiroshima
explosion. Three hours before the explosion, engineers noticed
a drop in the pressure, but they turned up the pressure back to
normal instead of checking for leaks.[4]